Review: 2022 Vitus Sommet 297 AMP - Good Performance, Great Price

There are four models in the range, starting at £2,700 and running to £4,600. All use the same frame, with a carbon mainframe mated to an alloy rear end. Vitus chose to send me the top-tier AMP model, which uses a mix of high-end SRAM parts and Nukeproof finishing kit. To be honest, the cheaper models look like better value on paper, especially the entry-level CR (£2,700), which uses a Deore drivetrain and RockShox Domain fork, or the second tier CRX (£4,000), which has Fox Factory suspension and full Shimano XT groupset.

That's not to say the top model is a disappointment, though. With top-end SRAM suspension and components, plus a carbon handlebar and crank making it the lightest of the range and respectably light considering the price and the suspension travel. But how does it ride?

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Frame Details


The frame isn't the most flashy or feature-packed, but it offers everything you'd expect from a modern enduro bike: room for a full-size water bottle, a threaded bottom bracket, internal cable routing, rubber chainstay and downtube protection, UDH compatability and ISCG tabs. The cable routing may not be the neatest, especially under the bottom bracket, but it doesn't rub or rattle. There are no tube-in-tube cable guides, just foam tubes and wide ports to guide the cables through. Vitus say they couldn't hit the price point they wanted with moulded cable tubes.


There's a flip-chip located at the lower shock eyelet, which gives a 6mm change to the BB height and a 0.5-degree change to the head and seat tube angles. The carbon mainframe is the same between the mullet and 29" versions of the bike, but the seatstay and chainstay are wheel-size specific, so there's no option to fit a 29" rear wheel in here. You could put a smaller rear wheel in the 29er, but a 27.5" wheel has a 19 mm smaller radius, so the 6 mm flip-chip adjustment won't compensate for that. Tire clearance is 2.6" on the 297, or 2.5" on the 29er. One thing you don't see that often is internal cable routing in the top tube for a remote shock lockout cable. None of the stock models are specced with a remote lockout, but it's always nice to have options.

Geometry & Sizing


When comparing the above geometry chart from Vitus to my own measurements, most of the numbers match reality to within a few millimetres, except the wheelbase of my XL test bike measures 1,310mm, not 1,288. It's normal for manufacturers' geometry charts to be a little off, but that's quite a big difference. The head angle of my bike measures 63-degrees, and the effective seat angle at my pedalling height (82cm from BB to saddle-top) is 76-degrees. The bottom bracket height is 342mm. All these measurements are in the low setting.

Suspension Design

Vitus have gone with a classic Horst-link suspension layout (using a chainstay pivot in front of the rear axle) but unlike sister-brand Nukeproof, they use a vertically-mounted shock and a rocker link that rotates in the same direction as the chainstay.

Vitus designed the anti-squat levels (how much the suspension resists compressing while pedalling) to be on the low side in order to keep pedal kickback to a minimum, arguing that this helps suspension sensitivity. According to their numbers, the anti-squat ranges between 100 and 110% depending on the gear, which in theory would mean the rear suspension wouldn't compress at all when force is applied to the pedal, but in the real world, it does squat and bob more than many comparable bikes.

I asked Vitus how they generated their numbers and it turns out they had assumed a centre of gravity height that was 650 mm above the bottom bracket. Some of the graphs you'll see elsewhere (including those by Pinkbike's Dan Roberts) assumes a higher COG than this, and when I'm riding the bike, the centre of gravity will be higher still. With a higher COG, the lower the true anti-squat and anti-rise values will be, and so the more the bike will squat when pedalling and dive when braking out in the real world.

Specifications

The once-common RockShox Reverb makes a rare appearance on the Sommet Amp, which works great and, with its hydraulic hose, makes it easier to move the post up or down in the frame than cable-operated posts, but its travel is limited to 175mm. Vitus chose a 30-tooth chainring along with a 10-52 tooth cassette, which along with the 27.5" back wheel, makes for a super low bottom gear. A good choice for "real riders" in my view - myself included. Vitus spec 200mm rotors front and rear, but the smaller rear wheel effectively makes the rear brake more powerful than the front, due to the lower mechanical advantage of the smaller wheel radius. Personally, I found this caused me to skid the rear wheel too easily, so I'd upsize the front or downsize the rear.

Clever details include the DoubleDown rear tire and MaxxGrip EXO+ front tire, offering grip and protection where it's most needed. I'm happy to see the Nukeproof Horizon V2 wheels which I reviewed recently, but the carbon crank and handlebar are flashy for the sake of it in my view.

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Climbing

As you may have guessed by the saddle position, I found the seat angle a bit too slack in combination with the long-travel suspension, making it feel less eager and efficient when tackling steep climbs. The suspension bobs up and down more than most bikes of this travel too, and this unwanted suspension movement makes it feel less efficient than many enduro bikes. Don't get me wrong, it's not a bad climber, but there are better climbing enduro bikes these days, especially when things get steep. Switching to the high setting would improve the climbing position slightly, but I preferred the low setting for descending and that's what this bike is about.

For steep and smooth sections, I just flicked the shock's climb switch, which cuts the bob and makes the bike sit up a bit more too. Combined with that super low bottom gear, this means you can winch up even 20% gradients without having to mash the pedals at a plodding cadence. Scoff if you like, but a lower bottom gear is nice to have in some situations (and no, I'm not horrendously unfit), though I'd definitely shift up a gear or two for technical climbs. Speaking of which, there comes a point where the locked-out shock isn't ideal for rougher pedals, so I found myself switching between the two settings more often than I'd like.

Descending

Although it was quick and easy to get a decent starting setup, it took a lot longer to get the most out of the Sommet.

Out of the box, with just under 30% sag, the rear suspension isn't particularly supportive. It moves through its travel quite readily in berms and compressions, making the bike a bit less engaging and settled than I'd like. The Zeb fork isn't the most supportive in the middle of its travel either, which in a way makes the balance better, but the lack of support from the rear suspension is what I noticed especially in flowing terrain with berms and jumps. The leverage curve is progressive throughout, so I'd put this down to the shock's compression tune.

The obvious solution is to increase the spring rate and run less sag on the rear or increase compression damping. I tried going from 190 psi to 210 psi, but this noticeably increases harshness over small bumps and near the start of the travel. A better solution was to add a volume spacer with the pressure at 200 psi, and I added more low-speed compression for tracks with big undulations.


The main thing which held it back for me was the bar height. With just 20 mm of spacers to play with, the bar was too low at the highest position, which makes it difficult to keep pressure on the front wheel while keeping my weight centred between the axles when tackling steep descents with big steps and holes. Swapping to a 40 mm rise handlebar made a world of difference, allowing me to tackle these steep sections comfortably. Even with these modifications, the Sommet's suspension isn't the most composed and supportive when pushing into compressions; the chassis rocks back and forth more than some bikes on steep, technical terrain with big holes and steps. I'd put a lot of this down to the RockShox Zeb fork, which pushes through the middle part of its travel a bit too easily. Despite this, the long front-end and slack head angle mean it's easy to attack steep, technical sections with confidence.

When the gradient levels out, the relatively short chainstay and long front centre (on the Xl size) can be a bit of a handful of flat, loose turns, as there's less weight on the front wheel. This will be less of an issue for smaller frame sizes though. The flip side is that it's easy to loft the front wheel and place the back wheel on steep terrain, but personally, I'd prefer a longer back end.

The Sommet is in its element on fast, rough sections, where the long front centre and active suspension allow you to plow through the rough and look further ahead. While the small back wheel still gets hung up on one-off, square edge bumps more than a 29er, when it comes to fast sections of braking bumps, roots or rocks, it irons things out beautifully even when compared to full 29ers I've tested lately - including the Canyon Strive and Nukeproof Giga. There's loads of bottom-out resistance when set up with three volume spacers, too. That makes it hugely enjoyable on bike park-style terrain.

How Does it Compare?

Comparing the £4,600 Vitus to a £6,000 Canyon may sound unfair, but the Strive has a more affordable stablemate. At £4,749, the Strive CFR Underdog is in the same price bracket as the Sommet AMP and has only superficial downgrades compared to the top-spec Strive I reviewed recently. When climbing, both bikes are evenly matched if the Strive is restricted to its descending mode, but flick the Shapeshifter button and the Canyon is noticeably more sprightly and upright.

On the descents, the Strive is a little more stable, not so much because of the geometry (the wheelbase is almost identical) but because of the suspension. The Fox fork and shock offer more mid-stroke support, and the Strive's suspension is more settled under braking, so there's less pitching and diving when hard on the anchors or pushing into compressions. At the same time, the Canyon seems to offer better small-bump sensitivity and traction. Both bikes had similar tires, but the Vitus was more prone to slide at the rear. On the other hand, the Sommet's 170 mm of rear-wheel travel and more active mid-stroke allow it to plough through fast choppy sections with a little less feedback.

It would have been a more interesting comparison if Vitus sent the Fox-equipped CRX model, and the further down the price list you go, the more Vitus's value stands out against similarly-priced rivals.

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Technical Report


SRAM X01 drivetrain: I've ridden a few bikes with SRAM AXS lately but the mechanical equivalent still feels more intuitive to me. I prefer the shifter ergonomics of the mechanical version - yes, I've tried switching over the button functions in the AXS app - and as long as it's set up properly, it just works and is less of a distraction while riding. The huge gap from 1st to 2nd gear isn't ideal, but thanks to the small chainring you could always switch to a 10-50t cassette and still have a super low climbing ratio.

Nukeproof Sam Hill Grips: I like the shape and the soft compound these have, but the outer lock ring sticks out a long way from where my hands sit, ready to catch trees. One of the grips broke in a crash where the plastic part enters the outer lock ring, so I borrowed a replacement from a Nukeproof test bike. A single lockring version with the same rubber compound and shape would be superb.

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Reviews and Tech Reviews Enduro Bikes Vitus Vitus Sommet